How many subclasses of IgG are there?

Immunoglobulin G (IgG) is a crucial antibody in the human immune response, and it is classified into different subclasses based on structural and functional characteristics. There are four recognized subclasses of IgG: IgG1, IgG2, IgG3, and IgG4. Each subclass has distinct properties and functions, contributing to the immune system's ability to respond to different types of pathogens.

This classification is important because different subclasses of IgG have varying abilities to activate complement, bind to antigens, and mediate immune responses. For instance, IgG1 is particularly effective in opsonization, while IgG3 is adept at activating the complement system. Understanding these subclasses helps in diagnosing and treating various diseases, especially autoimmune disorders and infections, making it essential knowledge for medical technologists in the field of immunology.